The invention relates to an apparatus for introducing shock waves into a living body via at least one element which transmits the shock waves and on which shock pulses act, at least one spring member serving to generate the shock pulses. The apparatus is preferably designed as a medical handheld appliance which can be used both in intracorporeal shock wave lithotripsy and in extracorporeal shock wave orthopedics as part of the disintegration of calculi or superficially in the case of diseased parts of the body.
A device of this kind is generally known for example from U.S. Pat. No. 4,549,535 for the treatment of humans. Since it has a soft tip, it cannot be used for lithotripsy.
The disintegration of concretions in vivo by the use of shock waves (lithotripsy) is already used successfully in modern medicine. The concretions, such as kidney stones, are disintegrated in the body of a human into small fragments, which are then intended to be excreted from the body via the urinary tract.
In the present case, a shock wave is understood to mean in particular any compression wave generated by an impact.
The prior art describes various apparatuses and methods for generating shock waves for disintegrating concretions in a living body. Thus, the U.S. Pat. No. 5,868,756 describes a handheld appliance for use in intracorporeal shock wave lithotripsy, said appliance having a probe which serves as a waveguide for transmitting shock waves and is dimensioned in an appropriate manner for introduction into an endoscope.
The shock energy for generating the shock waves is obtained in this handheld appliance by a projectile or percussion part that can move back and forth pneumatically in a guide tube, specifically in that it periodically strikes an appropriately large mass part which then transfers the impact force acting on its target area to the probe adjoining the mass part.
This US document also states that instead of a pneumatic drive for the percussion part, a hydraulic or electromagnetic drive can alternatively be realized.
Furthermore, DE 197 25 477 C2 describes a medical instrument in the form of a handheld appliance for treating biological tissue (orthopedics), said medical instrument being intended to generate extracorporeal pressure waves. These pressure waves are intended to be introduced into the body of living beings with the aid of a transmitting element. To this end, the transmitting element has a blunt probe tip having a flat output interface, by way of which unfocussed, mechanically generated pressure waves can then be coupled into the biological tissue.
In this instrument, the pressure wave itself is generated by a percussion part that is accelerated pneumatically to a speed of more than 5 m/s and impinges on the transmitting element, it being intended that the probe tip execute a stroke of less than 1 mm. With this handheld appliance, it is further intended that the energy of the pressure waves be distributed evenly over a large region of action, such as an entire region of inflammation, for example.
For example, U.S. Pat. No. 1,796,444 discloses an apparatus for treating the human body with shock waves. In order to generate the shock waves, a spring element is tensioned and then abruptly released. The tensioning device for the spring element is a drive. Disadvantageously, a sudden, abrupt triggering is not possible therewith, since the spring element remains connected to the tensioning device the whole time.
However, the known handheld appliances all have pressure or shock wave generators, and have relatively complicated designs since a compressor, control unit and handpiece are required.
It is an object of the invention to provide an apparatus for introducing or applying shock waves into or onto a living body, the shock wave generator of which has a simple structure and also delivers an exact “hard” impact force. Furthermore, the apparatus should be low-maintenance and be highly suitable for intra- and for extracorporeal treatment, preferably of the human body.